1. The combination of the tank G and its adjustable plunger H with the atomizer or spraying devices of the engine, substantially as and for the purpose herein set forth.

2. The combination, with the atomizer I K, of the gas generator M, and its attached burner O, and the air-valve m, automatically controlled by the governor V of the engine, essentially as and for the purposes herein set forth.

3. The combination of the air-supply valve m, spring r, and rod s, sleeve T and governor V with the petroleum-injector I of the atomizer, essentially as specified.

4. The combination, with the cylinder A and the petroleum-injector I, of the air-nozzle K, having an automatically-operating valve, d, substantially as shown and described.

5. The combination of the air-compressor L with the gas generator M, the gasometer P, the nozzle g', the burner O, and the cylinder A, having an aperture, k, controlled by a valve, l, essentially as and for the purpose herein set forth.

The efforts which have hitherto been made to employ these hydrocarbons, such as petroleum, &c., have taken the direction of tis use as an indirect agent subserving merely the purpose of evaporating water in a boiler into steam, whereof the expansive power supplies the initial force required. In some cases boilers have been fitted with appliances for simply distributing petroleum, in a liquid state, over and among the ordinary fuel used for firing purposes : in a more advanced stage, combustion, having been initiated in the boiler-furnace in the ordinary way, by fuel on the fire-bars, is maintained by supplies of liquid hydrocarbon, forced into the fire-chamber by means of a steam injector, so that it enters as spray, in a finely subdivided state, favourable for rapid ignition and perfect combustion : in another system, adopting the process of generating an air-gas, by forcing atmospheric air through petroleum or other liquid hydrocarbon in a tank - as commonly practised for illuminating purposes  - such air gas is conveyed to a series of perforated pipes, or burners, placed within the horizontal tubes of a tubular boiler, and by inflaming the issuing gas-jets supplies the heat necessary to evaporate the water in the boiler into steam. 

Something of these principles, differently applied, may be seen in Hock's petroleum prime-motor, under consideration, which is thoroughly illustrated "en gros et en détail"  in the accompanying gravings. Liquid hydrocarbon, in small quantities, is injected by atmospheric pressure, not by steam, not into a fire-box, but directly into a cylinder, which becomes the combustion chamber; issuing in the usual form it is at once distributed and divided by an atmospheric jet, serving the double purpose of dispersing and partly vaporising it in the form of spray, and of partially diluting it with a small admixture of air, which is a constant quantity ; further atmospheric diluent is supplied through an air-shown, on a somewhat large scale, in the side elevation, Fig. 2, and in the end elevation, Fig. 3. The engine is carried on an ordinary cast-iron bed-framing, to which are bolted down the cylinder and the brackets carrying the bearings of the crankshank, fly-wheel V, and driving pully ; O ; upon the shaft is also fitted an eccentric with rod and buffer T, striking upon a hemi-spherical caoutchouc disc R, acting as an intermittent air-pump, and connected by pipes with the apparatus for generating air-gas, H, which is placed independently on one side of and adjacent to the frame. The engine is also fitted with a governing and regulating mechanism, comprising mainly two parts ; the customary governor balls and connections f f, driven by belt from a pulley on the crank-shaft adjoining the fly-wheel ; and a valve box X, attached to one side of the cylinder, with spring and rod W W, and actuated by an eccentric on the other end of the crank-shaft, close to the driving pulley ; a second eccentric works a cold-water pump U, whereby water is supplied continuously for cooling the cylinder, so that its temperature may not exceed a certain prescribed limit.